Supplementary Material for: Simulated patients to demonstrate common stroke syndromes: accurate and convincing

Introduction Stroke detection in the preclinical setting is challenging, resulting in more than 1/3 of missed strokes by EMS personnel. Recently, prehospital identification of anterior large vessel occlusion (LVO) stroke has come into focus. Cortical signs have a high predictive value for the presence of LVO stroke but are often missed. Simulated patients (SPs) could be an excellent tool to train EMS personnel in the evaluation of stroke syndromes with cortical symptoms but it has not been studied whether they can simulate these important signs convincingly. The main objective of this study was thus to examine whether SPs can simulate stroke syndromes and symptoms so that stroke experts can identify them correctly and reliably, applying the NIH stroke scale (NIHSS). Methods Lay actors were trained to simulate one of 8 stroke syndromes either typical of a lacunary stroke or of an anterior LVO stroke and then videotaped during an examination according to the NIHSS. Stroke experts were asked to rate each item of the NIHSS based on the videos, determine which stroke syndrome was being demonstrated, and rate the quality of the simulation. The primary outcome was the correct identification of the target stroke syndrome by the expert raters. Secondary outcomes were the agreement of the rating of the NIHSS score with the target NIHSS score and the expert raters’ assessment of the quality of the simulation. Results Seven of eight syndromes were rated correctly by at least twelve of fifteen raters and the mean rated NIHSS score was within one point of the target score for six of eight syndromes. The mean rating for the quality of simulation was between 3.54 and 3.98 (as rated on a scale from 1 to 4) for each syndrome. Discussion/Conclusion SPs are capable of simulating acute stroke symptoms and syndromes accurately and convincingly. They thus represent a great resource to improve educational interventions that improve stroke recognition.

引言
临床前场景下的卒中检测颇具挑战，导致急诊医疗服务（Emergency Medical Services, EMS）人员漏诊超过三分之一的卒中病例。近年来，前循环大血管闭塞（Large Vessel Occlusion, LVO）卒中的院前识别成为研究热点。皮质体征对于LVO卒中的存在具有较高预测价值，但常被漏诊。模拟患者（Simulated Patients, SPs）或是训练急诊医护人员评估伴皮质症状的卒中综合征的优质工具，但目前尚未有研究证实其能否逼真地模拟此类重要体征。因此本研究的主要目的是探究模拟患者能否精准模拟卒中综合征与症状，使得卒中专家能够借助美国国立卫生研究院卒中量表（National Institutes of Health Stroke Scale, NIHSS）对其进行准确可靠的识别。
方法
招募普通演员接受训练，使其能够模拟8种卒中综合征中的一种——这些综合征要么典型表现为腔隙性卒中，要么为前循环LVO卒中——随后根据NIHSS量表进行检查的过程被录像。卒中专家需根据录像对NIHSS量表的每一项进行评分，判断录像中展示的是何种卒中综合征，并对模拟质量进行评级。本研究的主要结局指标为专家评级者能否准确识别目标卒中综合征；次要结局指标包括NIHSS评分评级与目标NIHSS评分的一致性，以及专家评级者对模拟质量的评估结果。
结果
8种综合征中的7种可被15名评级者中的至少12名准确识别；8种综合征中的6种的平均NIHSS评分评级与目标评分的差值在1分以内。各类综合征的模拟质量平均评级介于3.54至3.98之间（评级量表为1至4分）。
讨论与结论
模拟患者能够精准且逼真地模拟急性卒中症状与综合征，因此其可作为优质资源，用于优化提升卒中识别能力的教育干预方案。